Optical imaging with reduced immersion liquid evaporation effects

Abstract

An optical arrangement for use in an optical imaging process includes an optical element, an immersion zone and a liquid repelling device. During the optical imaging process, the immersion zone is located adjacent to the optical element and is filled with an immersion liquid. The optical element has a first surface region and a second surface region. During the optical imaging process, the first surface region is wetted by the immersion liquid. At least temporarily during the optical imaging process, the liquid repelling device generates an electrical field in the region of the second surface. The electrical field being is adapted to cause a repellent force on parts of the immersion liquid which are responsive to the electrical field and inadvertently contact the second surface region. The repellent force has a direction to drive away the parts of the immersion liquid from the second surface region.

What is claimed is: 
     
       1. An optical arrangement, comprising:
 an optical element having first and second surface regions; and 
 a liquid repelling device comprising an electrically conductive element adjacent the optical element, 
 wherein:
 the electrically conductive element is mechanically connected to the optical element and contacting the optical element; and 
 during an optical imaging process performed using the optical arrangement:
 an immersion zone is adjacent to the optical element and contains an immersion liquid; and 
 the first surface region is wetted with the immersion liquid. 
 
 
 
     
     
       2. The optical arrangement of  claim 1 , wherein during the optical imaging process performed using the optical arrangement:
 at least temporarily, the liquid repelling device generates an electrical field in the region of the second surface; and 
 the electrical field is generated via the electrically conductive element. 
 
     
     
       3. The optical arrangement of  claim 2 , wherein the electrical field is an electrostatic field. 
     
     
       4. The optical arrangement of  claim 2 , wherein, during the optical imaging process performed using the optical arrangement, the electrical field is configured to cause a repellent force to drive away a portion of the immersion liquid in contact with the second surface region. 
     
     
       5. The optical arrangement of  claim 4 , wherein:
 the electrically conductive element comprises a first electrically conductive element located in the region of the first surface region; and 
 during the optical imaging process performed using the optical arrangement:
 the electrical field comprises a first electrical field generated via the first electrically conductive element; and 
 the first electrical field is configured so that the repellent force comprises a first repellent force component acting as an attractive force between the portion of the immersion liquid in contact with the second surface region and the first electrically conductive element. 
 
 
     
     
       6. The optical arrangement of  claim 5 , wherein:
 the first electrically conductive element has a surface region; 
 during the optical imaging process performed using the optical arrangement, the surface region of the first electrically conductive element faces the immersion fluid; 
 a cover element covers the surface region of the electrically conductive element; and 
 the cover element is electrically insulating and/or hydrophilic. 
 
     
     
       7. The optical arrangement of  claim 6 , wherein the cover element comprises at least one material selected from a material group consisting of a silicon dioxide, aluminum oxide, hafnium oxide and tantalum pentoxide. 
     
     
       8. The optical arrangement of  claim 4 , wherein:
 the liquid repelling device comprises a second electrically conductive element located in the region of the second surface region of the optical element; and 
 during the optical imaging process performed using the optical arrangement:
 the electrical field comprises a second electrical field generated via the second electrically conductive element; and 
 the second electrical field is configured so that the repellent force comprises a second repellent force component acting as a repulsive force between the portion of the immersion liquid in contact with the second surface region and the electrically conductive element. 
 
 
     
     
       9. The optical arrangement of  claim 8 , wherein:
 the second electrically conductive element has a surface region; 
 during the optical imaging process performed using the optical arrangement, the surface region of the second electrically conductive element faces the immersion fluid; 
 a cover element covers the surface region of the electrically conductive element; and 
 the cover element is electrically insulating and/or hydrophobic. 
 
     
     
       10. The optical arrangement of  claim 2 , wherein:
 the liquid repelling device comprises an electrical field generating device; 
 during the optical imaging process performed using the optical arrangement:
 the electrical field generating device at least temporarily generates a further electrical field; 
 to at least enhance a responsiveness of the immersion liquid to the electrical field generated via the liquid repelling device, the further electrical field provides a first effect and/or a second effect; 
 the first effect is an electrical polarization of at least a portion of the immersion liquid in contact with the second surface region of the optical element; and 
 the second effect is an electrostatic charge of at least the portion of the immersion liquid in contact with the second surface region of the optical element. 
 
 
     
     
       11. The optical arrangement of  claim 1 , wherein the electrically conductive element comprises at least one material selected from a material group consisting of chromium, aluminum, hafnium, titanium and nickel. 
     
     
       12. An optical arrangement, comprising:
 an optical element having first and second surface regions; and 
 a liquid repelling device comprising an electrically conductive element adjacent the optical element, 
 wherein:
 the electrically conductive element is mechanically connected to the optical element and contacting the optical element; and 
 during an optical imaging process performed using the optical arrangement:
 an immersion zone is adjacent to the optical element and contains an immersion liquid; 
 the first surface region is wetted with the immersion liquid; and 
 the liquid repelling device comprises an electrical field generating device configured to at least temporarily electrically contact the electrically conductive element. 
 
 
 
     
     
       13. An optical imaging device, comprising:
 an illumination device configured to illuminate an object comprising a pattern, 
 an optical projection device configured to project the illuminated pattern onto a substrate comprising an optical element group, 
 wherein the optical projection device comprises an optical arrangement according to  claim 1 . 
 
     
     
       14. An optical element, comprising:
 an optical element body having first and second surface regions; and 
 an electrically conductive element mechanically connected to and contacting the optical element in a region of the first surface region and/or the second surface region, 
 wherein, during an optical imaging process performed using the optical element, the first surface region is wetted with an immersion liquid responsive to an electrical field. 
 
     
     
       15. The optical element of  claim 14 , wherein the electrically conductive element is configured to be electrically charged to generate an electrostatic field as the electrical field. 
     
     
       16. The optical element of  claim 14 , wherein:
 the electrically conductive element comprises a first electrically conductive element located in the region of the first surface region; 
 the first electrically conductive element is configured to participate in generating the electrical field during an optical imaging process performed using the optical element; 
 the electrical field comprises a first electrical field generated via the first electrically conductive element; and 
 the first electrical field is configured so that the repellent force acts as an attractive force between a portion of the immersion liquid in contact with the second surface region and the electrically conductive element. 
 
     
     
       17. The optical element of  claim 14 , wherein:
 the electrically conductive element has a surface region; 
 during an optical imaging process performed using the optical element, the surface region of the electrically conductive element faces the immersion fluid; 
 a cover element covers the surface region of the electrically conductive element; and 
 the cover element is electrically insulating and/or hydrophilic. 
 
     
     
       18. The optical element of  claim 17 , wherein the cover element comprises at least one material selected from a material group consisting of a silicon dioxide, aluminum oxide, hafnium oxide and tantalum pentoxide. 
     
     
       19. The optical element of  claim 14 , wherein:
 the electrically conductive element comprises a second electrically conductive element located in the region of the second surface region; and 
 the electrically conductive element is configured to participate in generating the electrical field during an optical imaging process performed using the optical element; 
 the electrical field comprises a second electrical field generated via the second electrically conductive element; 
 the second electrical field is configured so that the repellent force comprises a second repellent force component that acts as a repulsive force between the portion of the immersion liquid in contact with the second surface region and the electrically conductive element. 
 
     
     
       20. The optical element of  claim 19 , wherein:
 the second electrically conductive element has a surface region; 
 during an optical imaging process performed using the optical element, the surface region of the second electrically conductive element faces the immersion fluid; 
 a cover element covers the surface region of the second electrically conductive element; 
 the cover element is electrically insulating and/or hydrophobic. 
 
     
     
       21. The optical element of  claim 14 , wherein the at least one electrically conductive element comprises at least one material selected from a material group consisting of chromium, aluminum, hafnium, titanium and nickel. 
     
     
       22. A method, comprising:
 intentionally wetting a first surface of an optical element with an immersion liquid; 
 inadvertently wetting a second surface of the optical element with a portion of the immersion liquid; and 
 using an electrically conductive element to generate a force that repels the portion of the immersion liquid which is inadvertently in contact with the second surface of the optical element, 
 wherein the electrically conductive element is mechanically connected to and contacting the optical element. 
 
     
     
       23. The method of  claim 22 , further comprising:
 using the electrically conductive element to generate an electrical field in a region of the second surface, 
 wherein the electrical field causes the repellent force on the portion of the immersion liquid to drive away the portion of the immersion liquid from the second surface region. 
 
     
     
       24. The method of  claim 23 , wherein the electrical field is an electrostatic field. 
     
     
       25. The method of  claim 22 , wherein:
 the electrically conductive element comprises a first electrically conductive element located in the region of the first surface region; 
 the first electrically conductive element is used to generate a first electrical field; and 
 the first electrical field is generated so that a first repellent force acts as an attractive force between the portion of the immersion liquid inadvertently in contact with the second surface region and the electrically conductive element. 
 
     
     
       26. The method according  claim 22 , wherein:
 the electrically conductive element comprises a second electrically conductive element located in a region of the second surface region; 
 the second electrically conductive element is used to generate a second electrical field; and 
 the second electrical field is generated so that a second repellent force acts as a repulsive force between the portion immersion liquid inadvertently in contact with the second surface region and the electrically conductive element. 
 
     
     
       27. The method of  claim 22 , further comprising electrically contacting the electrically conductive element to generate an electrical field. 
     
     
       28. The method of  claim 22 , further comprising:
 using the electrically conductive element to generate an electrical field; 
 generating a further electrical field is generated to enhance a responsiveness of the immersion liquid to the electrical field, providing a first effect and/or a second effect, 
 wherein the first effect is an electrical polarization of at least the portion of the immersion liquid inadvertently in contact with the second surface region, and the second effect is an electrostatic charge of at least the portion of the immersion liquid inadvertently in contact with the second surface region. 
 
     
     
       29. An optical imaging device, comprising:
 an illumination device configured to illuminate an object comprising a pattern, 
 an optical projection device configured to project the illuminated pattern onto a substrate comprising an optical element group, 
 wherein the optical projection device comprises an optical arrangement according to  claim 12 . 
 
     
     
       30. An optical imaging device, comprising:
 an illumination device configured to illuminate an object comprising a pattern, 
 an optical projection device configured to project the illuminated pattern onto a substrate comprising an optical element group, 
 wherein the optical projection device comprises an optical arrangement according to  claim 14 . 
 
     
     
       31. The optical arrangement of  claim 1 , wherein the electrically conductive element directly contacts the optical element.